Warp-beam brake



Nov. 1, 1960 w. GROB 2,958,341

WARP-BEAM BRAKE Filed April 21, 1958 Fig. I

trivia. 4

INVENTOR.

GIMM Un States Patemo WARP-BEAM BRAKE Willy Grob, 45 Burstwiesenstrasse, Zurich, Switzerland Filed Apr. 21, 1958, Ser. No. 729,866 Claims priority, application Switzerland Apr. 26, 1957 4 Claims. (Cl. 139-100) The present invention relates to a warp-beam brake and has for its primary object to render the movements of the warp beam caused by the throw of the reed as smooth as possible and to prevent slippage of the brake hand during the said throw of the reed (or when the warp expands or contracts when the loom is stopped).

During the throw of the reed during the opening and closing of the shed the warp beam usually performs a rotary movement so that the throw of the reed is not too heavy. A warp formed of strong warp yarn is insensitive to the blows of the reed but fine fabrics require an oscillatory movement of the warp beam which absorbs the blow of the reed. However, this movement must result in a slackening of the warp. For this reason it is very difficult in weaving fine fabrics to brake the Warp beam so that the tension admissible for the quality of the warp is obtained but not exceeded. With the known conventional rope brake, this condition is obtained by passing the rope three or four times around the brake ring for powerful braking, but only once or twice for slight braking. In brakes incorporating a brake drum with a brake band designed to effect braking, the specific contact pressure of the brake band on the brake drum is most important. If a relatively high braking power is to be exerted, the band should have the largest possible friction surface engaging so that a relatively small specific contact pressure enabling the adjustment to be obtained is obtained. When the braking power required for a fine warp, application of the same brake band causes the specific contact pressure to become so small that its adhesion will not sufiice to absorb the thrust of the reed.

The present invention has for its further object to eliminate this drawback by providing interchangeable brake bands of different widths, which damp the throw of the warp beam in both directions of rotation.

An embodiment of the invention is illustrated in the accompanying drawing in which:

Fig. 1 is a view of the warp-beam brake;

Fig. 2 is a plan view of the brake band connection seen in the direction of arrow A, and

Fig. 3 is a section along line IIIIII of Fig. 2.

Referring to the drawing, vertically sliding bearing-s 2 in the warp-beam creel carry :a shaft 3 of the warp beam. Provided on the warp-beam shaft 3 is a brake drum 5 on which one or more brake bands 6 are placed. Attached to one end of each brake band 6 is an angular member 7 while the other end carries a plate 8 to which a tensioning lever 9 is pivoted by means of a bolt 9a, the said lever being provided with a tensioning stirrup 10 having at least two detents for engaging a hook 11 of the angle member 12. The angle member 12 has a piece of lining 6a resting upon the drum 5. Each brake band can be tensioned by means of screw 13 connecting the angle members 7 and 12 and the wing nut 13a with the stirrup 10.

The brake bands are thus connected with the brake mechanism individually via the stirrup 10. Each brake band has both its ends provided with hooks 6b or plates 2,958,341- Patented Nov. 1, 196 0 "ice with a hook which can be engaged with the members 7 and 8 so that a brake band can be exchanged without removing these parts. Rigidly attached to the angle member 7 is the stop 15 which slides on rod 14 with its bore. The rod 14 is attached to a shaft 1a. Resting on a collar of rod 14 is a disk 16 which in turn supports the pressure spring 17. The pressure spring 17 is thus located between the stop 15 and the disk 16. A second pressure spring 18 is placed between the stop 15 and the disk 19. If the thrust is required to be damped with- 'out cushioning, the springs 17, 18 may be replaced by pads formed of a resilient material, such as cork, wood, leather and the like. By means of the nut 20 arranged on the thread of rod 14, the two pressure springs 17, 18 can be tensioned against one another. As far as the brake bands '6 are concerned several bands of different widths are associated with the brake drum of a warp beam so that a wide band can be used for coarse fabrics, and a narrow one for fine fabrics. Instead of arranging a brake band on the brake drum and of interchanging the bands, several brake bands of different widths can rest on the brake drum and those bands which are not required to brake are slackened by the tensioning lever 9 and the stirrup 10 by engaging the latter in a second detent. These arrangements are illustrated in Figs. 2 and 3. Fig. 2 shows a wide brake band 6 and a narrow band 60. Both the bands 6 and 6c are connected with a plate 8 and 8a respectively by means of a hook 6b (Fig. 1). The plates 8 and 8a respectively are provided with a tensioning stirrup 10 equipped with two detent bolts 10a. Riveted to the brake band section 6a (Figs. 1 and 3) which corresponds to the width of the brake drum and laterally engages the rims 5a of the brake drum 5 is a plate 512 to which the angle member 12 is attached. The angle member 12 and the plate 5b are slightly narrower than the brake band section 6a so that they will not engage the rims 5a of the brake drum. The angle member 12 is provided with several hooks 11 for engaging corresponding tensioning stirrups 10. It is also possible to attach to a plate 5b two angle members 12 of different widths each provided with a tensioning screw 13. This makes it possible to adjust the specific surface pressure to the braking action required so that braking without slippage is possible. When the warp beam moves in the direction of arrow a, i.e. in the direction of the reed contact, the spring 18 absorbs the thrust. It thereby stores the power contributing to the reverse motion of the warp beam. The pressure spring 17 is designed to take up the mass of the warp beam in the other direction of rotation so that the warp beam can readily oscillate between the two pressure springs.

This arrangement enables three difierent braking powers to be obtained by means of two brake bands, i.e. a small power by means of the narrow brake band 6c, a stronger one by means of the wide brake band 6 and a maximum one by means of the two brake bands, it being necessary to engage only one of the tensioning stirrups 10 with another detent.

This enables the tension of the warp to be immediately adjusted to the strain admissible for a particular fabric when the reed contacts.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is:

l. A Warpbeam brake, comprising in combination with a warp-beam shaft, a brake drum carried by said shaft, at least one brake band upon said brake drum, a plate, means connecting said plate to one end of said brake band, an angular member, means connecting said angular member to the other end of said brake band, a tensioning lever pivotally mounted upon said plate, a tensioning stirrup connected with said lever and having at least one detent, a lining upon said brake drum, an angle member carried by said lining and having a hook engaging said deten-t, a tensioning screw connecting said angular member with said angle member, a stop rigidly connected to said angular member, and resilient means pressing against opposite sides of said stop to secure said stop against rotation about the axis of said warp-beam shaft.

2. A warp beam brake in accordance with claim 1, wherein the means connecting the plate to one end of the brake band consist of a hook carried by the brake band and engaging the plate, and wherein the means connecting the angular member to the other end of the brake band consist of a hook carried by the brake band and engaging the angular member.

3. A warp-beam brake, comprising in combination with a warp-beam shaft, a brake drum carried by said shaft, a plurality of brake bands upon said brake drum, a separate plate for each brake band, separate means connecting each plate to one end of a separate brake band, a separate tensioning lever pivotally mounted upon each plate, a separate tensioning stirrup connected with each lever and having a plurality of detents, a lining upon said brake drum, an angle member carried by said lining and having a plurality of hooks adapted to engage various detents of said tensioning stirrups, at least one angular member, means connecting said angular member to opposite ends of said brake bands, at least one tensioning screw connecting said angular member with said angle member, a stop rigidly connected to said angular member, and resilient means pressing against opposite sides of said stop.

4. A warp beam brake in accordance with claim 1, wherein said brake bands are of different widths.

References Cited in the file of this patent UNITED STATES PATENTS Ritsky July 21, 1953 

